autofs-5.1.6 - sss introduce a flag to indicate map being read

From: Ian Kent <raven@themaw.net>

When the master map is being read for the first time a retry loop is

used by the caller to try harder to read the master map because it

is required for autofs to start up.

But when re-reading the master map, reading dependent maps, or doing

key lookups that loop isn't used so a longer retry is needed for those

cases.

Introduce a flag to indicate which map is being read, or if the master

map is being re-read, or if a key lookup is being done so the number

of retries can be adjusted accordingly.

Signed-off-by: Ian Kent <raven@themaw.net>

---

 CHANGELOG            |    1 +

 modules/lookup_sss.c |   87 +++++++++++++++++++++++++++++++++++++++++---------

 2 files changed, 72 insertions(+), 16 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG

index 4a6c042..2d98a3a 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -104,6 +104,7 @@ xx/xx/2018 autofs-5.1.5

 - improve sss getautomntent() error handling.

 - sss introduce calculate_retry_count() function.

 - move readall into struct master.

+- sss introduce a flag to indicate map being read.

 19/12/2017 autofs-5.1.4

 - fix spec file url.

diff --git a/modules/lookup_sss.c b/modules/lookup_sss.c

index 29666a3..3c0ffde 100644

--- a/modules/lookup_sss.c

+++ b/modules/lookup_sss.c

@@ -53,6 +53,24 @@

  */

 #define SSS_PROTO_VERSION 1

+#define SSS_DEFAULT_WAIT	10

+

+/* When the master map is being read a retry loop is used by the

+ * caller to try harder to read the master map because it is required

+ * for autofs to start up.

+ *

+ * But when reading dependent maps or looking up a key that loop isn't

+ * used so a longer retry is needed for those cases.

+ *

+ * Introduce a flag to indicate which map is being read or if a lookup

+ * is being done so the number of retries can be adjusted accordingly.

+ */

+#define SSS_READ_NONE		0x00

+#define SSS_READ_MASTER_MAP	0x01

+#define SSS_REREAD_MASTER_MAP	0x02

+#define SSS_READ_DEPENDENT_MAP	0x04

+#define SSS_LOOKUP_KEY		0x08

+

 unsigned int _sss_auto_protocol_version(unsigned int);

 int _sss_setautomntent(const char *, void **);

 int _sss_getautomntent_r(char **, char **, void *);

@@ -249,7 +267,7 @@ static unsigned int proto_version(struct lookup_context *ctxt)

 	return proto_version;

 }

-static unsigned int calculate_retry_count(struct lookup_context *ctxt)

+static unsigned int calculate_retry_count(struct lookup_context *ctxt, unsigned int flags)

 {

 	int retries;

@@ -269,15 +287,39 @@ static unsigned int calculate_retry_count(struct lookup_context *ctxt)

 		 * a host being down, return 0 for retries.

 		 */

 		if (proto_version(ctxt) == 0)

-			retries = 0;

+			return 0;

 		else

-			retries = 10;

+			retries = SSS_DEFAULT_WAIT;

 	}

+

+	if (proto_version(ctxt) == 0)

+		return retries;

+

+	/* When the master map is being read there's an additional

+	 * outer wait loop.

+	 *

+	 * If master map wait is set in the configuration there

+	 * will be an outer loop interating master_map_wait / 2

+	 * times so adjust the number of retries here to account

+	 * for this for the cases where the master map isn't being

+	 * read.

+	 */

+

+	if (!(flags & SSS_READ_MASTER_MAP) ||

+	     (flags & SSS_REREAD_MASTER_MAP)) {

+		unsigned int master_map_wait = defaults_get_master_wait();

+		unsigned int m_wait;

+

+		m_wait = master_map_wait ? master_map_wait : SSS_DEFAULT_WAIT;

+		retries *= (m_wait / 2);

+	}

+

 	return retries;

 }

 static int setautomntent_wait(unsigned int logopt,

-			      struct lookup_context *ctxt, void **sss_ctxt)

+			      struct lookup_context *ctxt, void **sss_ctxt,

+			      unsigned int flags)

 {

 	unsigned int retries;

 	unsigned int retry = 0;

@@ -285,7 +327,7 @@ static int setautomntent_wait(unsigned int logopt,

 	*sss_ctxt = NULL;

-	retries = calculate_retry_count(ctxt);

+	retries = calculate_retry_count(ctxt, flags);

 	if (retries == 0) {

 		if (proto_version(ctxt) == 0)

 			return EINVAL;

@@ -333,7 +375,8 @@ static int setautomntent_wait(unsigned int logopt,

 }

 static int setautomntent(unsigned int logopt,

-			 struct lookup_context *ctxt, void **sss_ctxt)

+			 struct lookup_context *ctxt, void **sss_ctxt,

+			 unsigned int flags)

 {

 	char buf[MAX_ERR_BUF];

 	char *estr;

@@ -355,7 +398,7 @@ static int setautomntent(unsigned int logopt,

 				goto error;

 		}

-		ret = setautomntent_wait(logopt, ctxt, sss_ctxt);

+		ret = setautomntent_wait(logopt, ctxt, sss_ctxt, flags);

 		if (ret) {

 			if (ret == ECONNREFUSED) {

 				err = NSS_STATUS_UNKNOWN;

@@ -400,13 +443,14 @@ static int endautomntent(unsigned int logopt,

 static int getautomntent_wait(unsigned int logopt,

 			 struct lookup_context *ctxt,

-			 char **key, char **value, void *sss_ctxt)

+			 char **key, char **value, void *sss_ctxt,

+			 unsigned int flags)

 {

 	unsigned int retries;

 	unsigned int retry = 0;

 	int ret = 0;

-	retries = calculate_retry_count(ctxt);

+	retries = calculate_retry_count(ctxt, flags);

 	if (retries == 0) {

 		if (proto_version(ctxt) == 0)

 			return EINVAL;

@@ -446,7 +490,8 @@ static int getautomntent_wait(unsigned int logopt,

 static int getautomntent(unsigned int logopt,

 			 struct lookup_context *ctxt,

-			 char **key, char **value, int count, void *sss_ctxt)

+			 char **key, char **value, int count,

+			 void *sss_ctxt, unsigned int flags)

 {

 	char buf[MAX_ERR_BUF];

 	char *estr;

@@ -486,7 +531,7 @@ static int getautomntent(unsigned int logopt,

 		}

 		ret = getautomntent_wait(logopt, ctxt,

-					 key, value, sss_ctxt);

+					 key, value, sss_ctxt, flags);

 		if (ret) {

 			if (ret == ECONNREFUSED) {

 				err = NSS_STATUS_UNKNOWN;

@@ -534,8 +579,13 @@ int lookup_read_master(struct master *master, time_t age, void *context)

 	char *key;

 	char *value = NULL;

 	int count, ret;

+	unsigned int flags;

+

+	flags = SSS_READ_MASTER_MAP;

+	if (master->readall)

+		flags |= SSS_REREAD_MASTER_MAP;

-	ret = setautomntent(logopt, ctxt, &sss_ctxt);

+	ret = setautomntent(logopt, ctxt, &sss_ctxt, flags);

 	if (ret)

 		return ret;

@@ -543,7 +593,9 @@ int lookup_read_master(struct master *master, time_t age, void *context)

 	while (1) {

 	        key = NULL;

 	        value = NULL;

-		ret = getautomntent(logopt, ctxt, &key, &value, count, sss_ctxt);

+		ret = getautomntent(logopt, ctxt,

+				    &key, &value, count,

+				    sss_ctxt, SSS_READ_MASTER_MAP);

 		if (ret) {

 			endautomntent(logopt, ctxt, &sss_ctxt);

 			return ret;

@@ -622,7 +674,8 @@ int lookup_read_map(struct autofs_point *ap, time_t age, void *context)

 		return NSS_STATUS_SUCCESS;

 	}

-	ret = setautomntent(ap->logopt, ctxt, &sss_ctxt);

+	ret = setautomntent(ap->logopt, ctxt,

+			    &sss_ctxt, SSS_READ_DEPENDENT_MAP);

 	if (ret)

 		return ret;

@@ -630,7 +683,9 @@ int lookup_read_map(struct autofs_point *ap, time_t age, void *context)

 	while (1) {

 	        key = NULL;

 	        value = NULL;

-		ret = getautomntent(ap->logopt, ctxt, &key, &value, count, sss_ctxt);

+		ret = getautomntent(ap->logopt, ctxt,

+				    &key, &value, count,

+				    sss_ctxt, SSS_READ_DEPENDENT_MAP);

 		if (ret) {

 			endautomntent(ap->logopt, ctxt, &sss_ctxt);

 			return ret;

@@ -711,7 +766,7 @@ static int lookup_one(struct autofs_point *ap,

 	mc = source->mc;

-	ret = setautomntent(ap->logopt, ctxt, &sss_ctxt);

+	ret = setautomntent(ap->logopt, ctxt, &sss_ctxt, SSS_LOOKUP_KEY);

 	if (ret)

 		return ret;